U.S. patent application number 14/780231 was filed with the patent office on 2016-02-25 for method and device for controlling an energy equivalence factor in a hybrid motor propulsion plant.
This patent application is currently assigned to RENAULT S.A.S.. The applicant listed for this patent is RENAULT S.A.S.. Invention is credited to Yann CHAMAILLARD, Guillaume COLIN, Maxime DEBERT.
Application Number | 20160052507 14/780231 |
Document ID | / |
Family ID | 48289443 |
Filed Date | 2016-02-25 |
United States Patent
Application |
20160052507 |
Kind Code |
A1 |
DEBERT; Maxime ; et
al. |
February 25, 2016 |
METHOD AND DEVICE FOR CONTROLLING AN ENERGY EQUIVALENCE FACTOR IN A
HYBRID MOTOR PROPULSION PLANT
Abstract
A method of determining an equivalence energy factor
representing weighting applied between an infeed of energy of
thermal origin and an infeed of energy of electrical origin, to
minimize on an operating point overall energy consumption of a
hybrid motor propulsion plant for an automotive vehicle including a
heat engine and at least one electric motor powered by a battery.
This factor is controlled in a discrete manner as a function of an
instantaneous state of energy of the battery, and of an energy
target, and as a function of the vehicle running conditions.
Inventors: |
DEBERT; Maxime; (Versailles,
FR) ; CHAMAILLARD; Yann; (Le Bardon, FR) ;
COLIN; Guillaume; (Olivet, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RENAULT S.A.S. |
Boulogne-Billancourt |
|
FR |
|
|
Assignee: |
RENAULT S.A.S.
Boulogne-Billancourt
FR
|
Family ID: |
48289443 |
Appl. No.: |
14/780231 |
Filed: |
March 29, 2013 |
PCT Filed: |
March 29, 2013 |
PCT NO: |
PCT/FR2013/050708 |
371 Date: |
September 25, 2015 |
Current U.S.
Class: |
701/22 |
Current CPC
Class: |
B60W 20/00 20130101;
B60W 10/06 20130101; B60W 2555/00 20200201; Y02T 90/14 20130101;
B60W 10/08 20130101; B60W 2050/001 20130101; B60W 2710/244
20130101; B60W 20/13 20160101; Y02T 10/40 20130101; B60W 10/26
20130101; B60W 2510/244 20130101; Y02T 10/7072 20130101; Y02T 10/84
20130101; Y02T 10/62 20130101; Y02T 10/70 20130101 |
International
Class: |
B60W 20/00 20060101
B60W020/00; B60W 10/08 20060101 B60W010/08; B60W 10/06 20060101
B60W010/06 |
Claims
1-8. (canceled)
9. A method for determining an energy equivalence factor
representing weighting applied between an infeed of energy of
thermal origin and an infeed of energy of electrical origin to
minimize at an operating point overall energy consumption of a
hybrid motor propulsion plant for a motor vehicle including a heat
engine and at least one electric motor powered by a battery, the
method comprising: controlling the energy equivalence factor in a
discrete manner based on an instantaneous state of energy of the
battery and based on a target energy and based on running
conditions of the vehicle.
10. The method for determining an energy equivalence factor as
claimed in claim 9, wherein the target energy is dependent on
predictions regarding the running conditions.
11. The method for determining an equivalence factor as claimed in
claim 9, having an integrated term regarding an estimation of a
state of energy of the battery.
12. The method for determining an equivalence factor as claimed in
claim 11, wherein the integrated term is dependent on the
difference between the target energy and the instantaneous state of
energy of the battery.
13. The method for determining an equivalence factor as claimed in
claim 12, wherein calculation of the term is looped by an integral
proportional calculation regarding a state of charge of the
battery.
14. The method for determining an equivalence factor as claimed in
claim 11, wherein the integrated term is looped by an anti-windup
factor.
15. The method for determining an equivalence factor as claimed in
claim 9, being pre-compensated by a term dependent on a conversion
yield of the electrical energy into mechanical energy.
16. A device for determining an equivalence factor as claimed in
claim 9, comprising a saturator between a minimum saturation and a
maximum saturation limit assuring control of forced recharge and
discharge modes.
Description
[0001] The present invention relates to the management of the
distribution of energy fluxes in a hybrid motor propulsion plant
for a motor vehicle.
[0002] More precisely, the present invention relates to the
determination of an energy equivalence factor representing the
weighting applied between the infeed of energy of thermal origin
and the infeed of energy of electrical origin, so as to minimize at
an operating point the overall energy consumption of a hybrid motor
propulsion plant for a motor vehicle, of the type comprising a heat
engine and at least one electric motor powered by a battery.
[0003] A motor propulsion plant for a motor vehicle with hybrid
propulsion or traction comprises a heat engine and one or more
electric machines, powered by at least one battery installed on
board the vehicle.
[0004] The systems for controlling hybrid motor propulsion plants
have been designed to manage the operation and the synchronization
of the different motors on the basis of running conditions so as to
limit the fuel consumption and so as to minimize the emissions of
polluting particles. Reference is made to the management of thermal
and electrical energy fluxes in order to designate, in particular,
the control strategy implemented in the control system with a view
to optimizing the distribution of power between the fluxes of
thermal energy and the fluxes of electrical energy. The principle
implemented in order to select the best operating point consists of
minimizing the sum of the thermal consumption and of the electrical
consumption by weighting the energy of electrical origin by a
weighting or equivalence factor.
[0005] This factor weights the electrical energy with the thermal
energy, i.e. it gives the quantity of fuel necessary to recharge a
certain amount of electrical energy stored in the battery or,
conversely, gives the quantity of fuel able to be saved by using a
certain quantity of energy originating from the battery. So that
the energy management strategy is optimal during a journey, it is
necessary for this equivalence factor to be unique and constant for
the given running conditions. This factor is dependent on a number
of parameters, such as the duration, length in kilometers of the
journey, the altitude profile encountered, the driving mode, the
ambient conditions (town, suburban zone, motorway, and so on),
etc.
[0006] Publication FR 2 935 123 discloses a system and a method for
controlling a hybrid motor propulsion plant equipped with a module
for determining an optimal operating mode and a module for
determining the operating point of the motor or motors in the
optimal operating mode. The system comprises a weighting means able
to influence the consumption of electrical energy and uses a
variable weighting coefficient in a manner inversely proportional
to the state of charge of the battery with a view to increasing the
weighting value when the battery is discharged and to reduce said
value when the battery is charged.
[0007] In accordance with this method the equivalence factor, or
weighting factor, is linearly dependent on the state of charge of
the battery. When the battery is empty the factor is high, which
tends to recharge the battery, and when the battery is full the
factor is low, which discharges the battery. The main advantage of
this type of control is the assurance of remaining within the
usable limits of the battery, i.e. between 0% and 100% of the state
of charge or "SOC" of the battery.
[0008] However, the disadvantages of this method are as follows:
[0009] the difficulty of adapting the equivalence factor on the
basis of the environment and of the driver, [0010] an
underestimation of the total energy use range of the battery, and
[0011] the absence of consideration of other ambient factors, such
as the running conditions.
[0012] Publication DE 1 032 3722 also discloses changing the
equivalence on the basis of certain running conditions. However,
the described method does not make it possible to take into
consideration the gradient of the road or the driving style of the
driver, nor does it make it possible to use the entire energy range
of the battery.
[0013] The present invention proposes a control method and device
ensuring optimized control of the equivalence factor with a view to
coming as close as possible to the optimal solution, taking into
account all the influencing factors.
[0014] The present invention with this objective proposes
controlling the equivalence factor in a discrete manner on the
basis of the instantaneous state of energy of the battery, and a
target energy depending on the vehicle running conditions and/or
predictions regarding the running conditions.
[0015] The proposed device in particular comprises an integrator of
a term representative of the difference between the instantaneous
state of energy of the battery and the target energy state.
[0016] Further features and advantages of the present invention
will become clear upon reading the following description of a
non-limiting embodiment thereof, given with reference to the
accompanying drawing, of which the sole figure schematically shows
the implemented device.
[0017] In this device a first comparator C1 receives, in input
values, the state of energy soe.sub.k of the battery at the moment
k, and target state of energy value soe.sub.target. The difference
(soe.sub.target-soe.sub.k) is multiplied by a correction gain
K.sub.p. A second comparator C2 sums the result
[K.sub.p(soe.sub.target-soe.sub.k)] and a correction term of the
integral type, which assures a correction of the equivalence factor
on the basis of the encountered running conditions. This sum is
saturated by the saturator S, which assures that the equivalence
factor will remain within the controlled limits. The minimum
saturation (sat.sub.min-1/.eta.) and maximum saturation
(sat.sub.max-1/.eta.) limits assure that forced recharge and
discharge modes are controlled.
[0018] The maximum saturation sat.sub.max is the maximum
equivalence value assuring a control of the motor propulsion group
such that the energy of the battery is recharged to the maximum.
The saturation sat.sub.min is the minimum equivalence factor
assuring a control of the motor propulsion group such that the
battery is discharged to the maximum. The integrator I integrates
the difference between the output of the saturator S and its own
integration multiplied by a correction gain K.sub.i with the aid of
the comparator C3. By integrating this difference, the integrator
cannot run out of control when the system is saturated. This method
is known by the name "anti-windup" or anti-racing or desaturator.
The output of the saturator is added with a term 1/.eta. of the
"feedforward" or pre-positioning term type with the aid of the
comparator C4. This "feedforward" or pre-positioning term makes it
possible to directly adapt the equivalence factor on the basis of
an encountered and/or predicted running situation.
[0019] To summarize, the proposed device comprises a loop
integrator of a term representative of the difference between the
instantaneous state of the energy of the battery and the target
energy state of the battery combined with an anti-windup device. It
also comprises a proportional compensation term.
[0020] The control implemented with this device also has a
feedforward term. The equivalence factor is controlled in a
discrete manner in accordance with the following equation:
S.sub.k+1=1/.eta..sub.c+Kp(soe.sub.target-soe.sub.k+1)+KpKi(soe.sub.targ-
et-soe.sub.k)
[0021] In this equation soe.sub.target is the target energy state
to be reached and soe.sub.k is the energy state of the battery at
the moment k. K.sub.p and K.sub.i are, respectively, the
proportional and integral correction gains; .eta.c is the mean
yield of conversion of the electrical energy into thermal energy.
The mean yield of conversion .eta.c may thus be calculated in order
to adapt permanently to the circumstances on the basis of the
knowledge a priori of foreseeable running conditions or on the
basis of analysis of the previous running conditions. The integral
correction provides a correction a posteriori of energy equivalence
hypotheses.
[0022] If, for example, a type of running "in congestion" is
identified, it is possible to provide the conversion yield
.eta..sub.c with a value suitable for situations of congestion and
to obtain an equivalence factor substantially different from the
equivalence factor on a motorway.
[0023] In addition, the desired target energy soe.sub.target can be
defined on the basis of the running conditions. If the vehicle has
a navigation system, it is then possible to utilize the information
provided thereby in order to optimize the target.
[0024] Lastly, when the equivalence is saturated, i.e. the
equivalence factor s reaches limit values, imposing a recharge or a
discharge of the battery at all costs, the equivalence factor s
does not exceed acceptable limits (lower and upper) because the
anti-windup avoids any untimely runaway of the integral term.
[0025] In conclusion, the invention makes it possible: [0026] to
use the energy contained in the battery more suitably and to draw
all possible benefits therefrom to reduce consumption, [0027] to
take into account the environment and the driver, [0028] to take
into account the altitude profile in the event that information is
provided via the navigation system, and [0029] to manage energy
fluxes based more on an "energy state" of the battery than on the
state of charge thereof, which is more advantageous in terms of
consumption.
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